FIG. 1 shows an optical network R in which a radio signal is transmitted via an optical fiber.
In such a network R, a first radio module Tx1 is connected to a first end of an optical link FO1 comprising two optical fiber segments, each of the segments of the optical fiber being associated with one transmission direction of an optical signal in order to allow a two-way transmission of the data. Such a radio module Tx1 is situated in a first room P1, of a domestic or business premises. A second end of the optical link FO1 is connected to two ports of a passive optical coupler N×N, in which for example N=6 as shown in FIG. 1. Such an optical coupler makes it possible to add together the various optical signals that it receives and then to broadcast this total to all the items of equipment that are connected thereto. A radio terminal T1, such as a personal computer fitted with radio emission/reception means such as an ultrawide band (UWB) processor, is also placed in the room P1 and is capable of emitting a radio signal to the radio module Tx1 and to receive a radio signal emitted by the radio module Tx1. Several radio terminals Tm can be connected to one and the same radio module Txi.
A second radio module Tx2 is connected to a first end of an optical link FO2. Such a radio module Tx2 is situated in a second room P2 of a domestic or business premises. A second end of the optical link FO2 is connected to two ports of the N×N coupler. A radio terminal T2 is also placed in the room P2 and is capable of emitting a radio signal to the radio module Tx2 and of receiving a radio signal emitted by the radio module Tx2.
The same applies to the radio modules Tx4, Tx5, Tx6 which are respectively connected to a first end of the optical links FO4, FO5, FO6. A second end of the optical links FO4, FO5, FO6 are respectively connected to two ports of the N×N coupler. Radio terminals T4, T5, T6 are respectively placed in the rooms P4, P5, P6 in which the radio modules Tx4, Tx5, Tx6 are respectively placed.
A radio terminal T3 is placed in a third room P3. Such a radio terminal T3 comprises radio management means GR and a radio module Tx3 connected to a first end of an optical link FO3. A second end of the optical link FO3 is connected to two ports of the N×N coupler. Such a radio terminal T3 is for example an item of equipment providing the interface between the network R and a second network I, such as the internet. In such a situation, the item of equipment providing the interface is a domestic gateway or an enterprise gateway depending on whether the network R is a domestic network or an enterprise network.
With reference to FIG. 2, a radio module Txi comprises emission/reception means ER/RR for emitting/receiving a radio signal and optical processing means 1 for processing a radio signal. The emission/reception means ER/RR are connected respectively to reception means RO of an optical carrier and to emission means EO of an optical carrier. The optical emission means EO are connected to a first optical fiber 11 forming an optical link FOi. The optical reception means RO are connected to a second segment of optical fiber 12 forming the optical link FOi. The emission/reception means EO/RO are included in the optical processing means 1.
When the radio signal is received by the radio reception means RR of the radio module Txi, it is transmitted to the optical emission means EO. The optical emission means EO modulate an optical carrier with the radio signal received by the radio reception means RR and intended to be transmitted over the optical link FOi. Once the optical carrier has been modulated, it is transmitted over the optical fiber segment 11. When the optical carrier is modulated, the data forming the radio signal remain in the native format of the radio signal.
When an optical carrier is received by the optical reception means RO, the latter demodulate the optical carrier. The data thus obtained are then transmitted to the radio emission means ER which then emit a radio signal to the radio terminal Tm.
When the radio reception means RR detect a radio signal, the latter is transmitted to optical emission means EO whether the detected radio signal is a radio signal comprising payload data or an interference radio signal containing no payload data. The optical emission means EO then modulate an optical carrier with the data included in the received radio signal, then the optical carrier is transmitted over the optical fiber segment 11 to the various radio modules Txi belonging to the network R. On reception of the optical carrier, the optical reception means RO of the various radio modules Txi of the network R generate a radio signal emitted by the radio emission means ER to the radio terminals associated with the radio modules.
The transmission of interference radio signals over the network generates noise disrupting the transmission of the payload radio signals and induces a loss in transmission byte rate. Such circumstances negatively impact the quality of service within the network R.